• 대한예방의학회:학술대회논문집
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• 대한예방의학회 2003년도 제11회 춘계 심포지움 연제집
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• pp.30-37
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• 2003

o Cohort study became the major approach to study of chronic diseases such as CVD and cancer o Cohort can be population-based or volunteer-based o Types of be population-be categorized by source population and selection mechanism o More and more cohort studies involve biological specimens, such as blood, urine, toenail, cheek cells, etc. o Multi-center and multi-national collaboration is an effective way to increase sample size. o Current statistical method typically use time-to-event analysis by Cox proportional hazard model.

• 보건행정학회지
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• 제28권4호
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• pp.378-391
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• 2018

Background: People who were born in different years, that is, different birth cohorts, grow in varying socio-historical and dynamic contexts, which result in differences in social dispositions and physical abilities. Methods: This study used age-period-cohort analysis method to establish explanatory models on healthcare expenditure in Korea reflecting birth cohort factor using intrinsic estimator. Based on these models, we tried to investigate the effects of ageing population on future healthcare expenditure through simulation by scenarios. Results: Coefficient of cohort effect was not as high as that of age effect, but greater than that of period effect. The cohort effect can be interpreted to show 'healthy ageing' phenomenon. Healthy ageing effect shows annual average decrease of -1.74% to 1.57% in healthcare expenditure. Controlling age, period, and birth cohort effects, pure demographic effect of population ageing due to increase in life expectancy shows annual average increase of 1.61%-1.80% in healthcare expenditure. Conclusion: First, since the influence of population factor itself on healthcare expenditure increase is not as big as expected. Second, 'healthy ageing effect' suggests that there is a need of paradigm shift to prevention centered-healthcare services. Third, forecasting of health expenditure needs to reflect social change factors by considering birth cohort effect.

• Journal of Preventive Medicine and Public Health
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• 제55권5호
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• pp.464-474
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• 2022

Objectives: We introduced the cohort studies included in the Korean Cohort Consortium (KCC), focusing on large-scale cohort studies established in Korea with a prolonged follow-up period. Moreover, we also provided projections of the follow-up and estimates of the sample size that would be necessary for big-data analyses based on pooling established cohort studies, including population-based genomic studies. Methods: We mainly focused on the characteristics of individual cohort studies from the KCC. We developed "PROFAN", a Shiny application for projecting the follow-up period to achieve a certain number of cases when pooling established cohort studies. As examples, we projected the follow-up periods for 5000 cases of gastric cancer, 2500 cases of prostate and breast cancer, and 500 cases of non-Hodgkin lymphoma. The sample sizes for sequencing-based analyses based on a 1:1 case-control study were also calculated. Results: The KCC consisted of 8 individual cohort studies, of which 3 were community-based and 5 were health screening-based cohorts. The population-based cohort studies were mainly organized by Korean government agencies and research institutes. The projected follow-up period was at least 10 years to achieve 5000 cases based on a cohort of 0.5 million participants. The mean of the minimum to maximum sample sizes for performing sequencing analyses was 5917-72 102. Conclusions: We propose an approach to establish a large-scale consortium based on the standardization and harmonization of existing cohort studies to obtain adequate statistical power with a sufficient sample size to analyze high-risk groups or rare cancer subtypes.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.815-822
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• 2001

The aim of this study is to estimate the seroconversion date of the human immunodeficiency virus(HIV) infection for the HIV infected patients in Korea. Data are collected from two cohorts. The first cohort is a group of "seroprevalent" patients who were seropositive and AIDS-free at entry. The other is a group of "seroincident" patients who were initially seronegative but later converted to HIV antibody-positive. The seroconversion dates of the seroincident cohort are available while those of the seroprevalent cohort are not. Estimation of seroconversion date is important because it can be used to calculate the incubation period of AIDS which is defined as the elapsed time between the HIV infection and the development of AIDS. In this paper, a Weibull regression model Is fitted for the seroincident cohort using information about the elapsed time since seroconversion and the CD4$^{+}$ cell count.The seroconversion dates for the seroprevalent cohort are imputed on the basis of the marker of maturity of HIV infection percent of CD4$^{+}$cell count.unt.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5891-5893
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• 2013

Incidence/mortality of liver cancer follow logistic curves because there is a limit reflecting the prevalence of hepatitis virus carriers in the cohort. The author fitted logistic curves to incidence/mortality data covering the nine five-year cohorts born in 1911-1955 of both sexes. Goodness-of-fit of logistic curves was sufficiently precise to be used for future predictions. Younger cohorts born in 1936 or later were predicted to show constant decline in incidence/mortality in the future. The male cohort born in 1931-35 showed an elevated incidence/mortality of liver cancer early in their lives supporting the previous claim that this particular cohort had suffered massive HCV infection due to nation-wide drug abuse in the 1950s. Declining case-fatality observed in younger cohorts suggested improved treatment of liver cancer. This study demonstrated that incidence/mortality of liver cancer follow logistic curves and fitted logistic formulae can be used for future prediction. Given the predicted decline of incidence/mortality in younger cohorts, liver cancer is likely to be lost to history in the not-so-distant future.

• 가정과삶의질연구
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• 제14권2호
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• pp.51-60
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• 1996

The purpose of this study is to identify the objective picture of developmental pattern of marital satisfaction of couples based on family life cycle length of marriage marriage cohort birth cohort and age of couples using data from 317 couples in urban cities. The result indicate that the U-curve of marital satisfaction is the special pattern of family life cycle while W-curve is more dominant pattern when data are analysed with length of marriage birth cohort and marriage cohort. The couples differ in their assessment of marital satisfaction through entire their life span which seems for wives to become more dissatisfied over time. The similarity of developmental pattern the spouses appears only in their birth cohort. Discussion and recommendations for future research of the marital satisfaction are suggested.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3951-3955
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• 2015

Background: Colorectal cancer mortality has started to decrease in several developed countries in Asia. The current study aimed to present the long-term trends in colorectal cancer mortality in Korea using joinpoint analysis and age-period-cohort modeling. Materials and Methods: The number of colorectal cancer deaths and the population for each 5-year age group were obtained from Statistics Korea for the period 1984-2013 for adults 30 years and older. Joinpoint regression analysis was conducted to determine changes in trends in age-standardized mortality rates, and age-period-cohort analysis was performed to describe trends in colorectal cancer mortality using the intrinsic estimator method. Results: In men, the age-standardized mortality rate for colorectal cancer increased from 1984 to 2003, and the mortality rates stabilized thereafter, whereas the mortality rate of colorectal cancer in women has decreased since 2004. The age-specific mortality rate of colorectal cancer increased in both men and women over time, whereas decreases in the age-specific mortality rate in younger cohorts were observed. In the age-period-cohort analysis, old age and recent period were associated with higher mortality for both men and women. The birth cohort born after 1919 showed reduced colorectal cancer mortality in both men and women. Conclusions: Our study showed a recent decreasing trend in colorectal cancer mortality in women and a stable trend in men after 2003-2004. These changes in colorectal cancer mortality may be attributed to birth cohort effects.

• 한국사회복지학
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• 제65권1호
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• pp.201-226
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• 2013

외환위기 이후 청년실업의 증가가 사회적 문제로 부각되었으나, 청년층의 노동시장 경험에 관한 연구는 제한적으로 이루어져 왔다. 본 연구에서는 노동경력을 단순한 일자리 이동과 달리 노동지위의 연속적 배열과 순서적이고 위계적인 변화과정으로 개념화하였으며, 배열분석을 활용하여 외환위기 전후 청년층의 노동경력을 노동지위의 다양한 측면에서 비교하였다. 분석 결과, 외환위기 이후 첫 일자리로의 이행기간이 장기화되고 고용형태와 사업장 규모 면에서 첫 일자리의 질적 저하가 발생하였음이 확인되었다. 또한 외환위기 이후 청년 코호트는 미취업형과 실업형, 비대기업형, 비정규직형 및 이동형 특성을 갖는 경력유형에 속할 상대적 위험률이 높았다. 이러한 결과는 전반적으로 외환위기 이후 청년층의 고용불안정성이 더 커졌으며, 내부노동시장형에 비해 외부노동시장형 경력유형이 상대적으로 증가한 것을 의미한다.

• 분석과 대안
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• 제8권2호
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• pp.31-64
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• 2024

최근 한국 국민의 통일필요 의식의 하락 추세는 선명하다. 통일필요 의식 하락 추세에 있어 출생 코호트 효과는 존재하는가? 본 연구의 목적은 통일필요 의식에 있어 출생 코호트가 통계적으로 유의미한 영향을 미치는지 분석하는 것이다. 이를 위해 분석모형으로 위계적 연령-기간-코호트(HAPC) 모형을 채용하였으며 2007~2021년 기간 서울대학교 통일평화연구원의 통일의식조사 데이터를 사용하였다. 분석 결과, 출생 코호트 수준에서 경제불평등의 진행이 통일 필요성 인식 하락에 영향을 미쳤다는 증거가 관찰되었다. 소득과 자산의 양극화 진행으로 인해 사회 진출 과정에서 사회경제적 어려움을 겪은 1980년대 출생 코호트는 막대한 재원이 투입되는 남북통일에 대해, 1960년대와 1970년대 출생 코호트와 비교해 선명하게 부정적인 인식을 가지는 것으로 판단된다.

• 농촌계획
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• 제12권3호
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• pp.39-42
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• 2006

The purpose of this study is to develop rural population model adapting cohort survival method with sift-share effects. Administrative district in this study is below Myun: about 2,000 population. Population data of rural area in 1990, 1995, and 2000 by age cohort were selected for applying developed model. Damping coefficient from population data was calculated as 7% and results applying this coefficient in rural population data below the error from 12% to 1.06%. In detail, most of cohorts fitted with developed model except from 15 to 29 age groups. Application result of small population area; DaesulMyun revealed that main factor of population change is not natural change but migration.